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Isolation and Functional Analysis of Mitochondria from Cultured Cells and Mouse Tissue
Published on: March 23, 2015
Fall in circulating mononuclear cell mitochondrial DNA content in human sepsis
Angela Pyle1, David J Burn, Charlotte Gordon
1Mitochondrial Research Group, Institute for Ageing and Health, The Medical School, Newcastle University, Framlington Place, Newcastle, NE2 4HH, UK.
Intensive Care Medicine
|March 13, 2010
Summary
In severe sepsis, whole blood mitochondrial DNA (mtDNA) depletion is mainly due to increased neutrophils. However, actual mtDNA depletion occurs in mononuclear cells and links to disease severity.
Area of Science:
- Mitochondrial DNA research
- Sepsis pathophysiology
- Cellular biology
Background:
- Mitochondrial DNA (mtDNA) loss in whole blood is observed in sepsis.
- The mechanism and clinical relevance of this mtDNA loss are unclear.
Purpose of the Study:
- Investigate the cellular basis of mtDNA depletion in sepsis.
- Determine clinical correlates of mtDNA depletion in sepsis patients.
Main Methods:
- Collected whole blood samples from 147 severe sepsis patients and 83 controls.
- Analyzed mtDNA content in whole blood and separated leukocyte subsets (monocytes, lymphocytes, neutrophils) from 13 sepsis patients.
- Utilized PCR and flow cytometry for mtDNA quantification and cell sorting.
Main Results:
- Septic patients showed significantly lower whole blood mtDNA content than controls (P < 0.0001).
- Increased neutrophil proportion, with 3-fold less mtDNA, largely accounted for whole blood mtDNA reduction.
- Isolated monocytes (P = 0.041) and lymphocytes (P = 0.021) from septic patients exhibited significant mtDNA depletion.
- Mononuclear cell mtDNA depletion correlated with APACHE II scores (P = 0.015), indicating disease severity.
Conclusions:
- Apparent whole blood mtDNA depletion in sepsis is primarily an artifact of altered leukocyte differential.
- True mtDNA depletion occurs in mononuclear cells (monocytes and lymphocytes) during severe sepsis.
- This mononuclear cell mtDNA depletion is a biomarker for sepsis severity.
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